Hot air furnace



March 28, 1961 w. wYc o r 2,976,917

HOT AIR FURNACE Filed Dec. 25, 1957 2 Sheets-Sheet 1 INV CR5. 7 M 2 5%,; 7. z/swad.

March 28, 1961 P. w. WYCKOFF ETAL 27,976,917

HOT AIR FURNACE 2 Sheets-Sheet 2 Filed Dec. 23, 1957 arrazwvz/q United States Patent M HOT AIR FURNACE Paul W. Wyckolf and Robert P. Wonka, Dayton, Ohio, assignors to Chrysler Corporation, Highland Park, Mich.,.a corporation of Delaware Filed Dec. 23, 1957, Ser. No. 704,653

1 Claim. (Cl. 158-7) This invention relates to a hot air furnace and more particularly to an arrangement of the components thereof for more eflicient utilization of the available heat exchanger surfaces.

Heretofore it has been common practice to provide a burner which emits flame in an upward direction and to locate this burner in the lower portion of a heat exchanger. However, with such an arrangement the bottom wall of the heat exchanger remains relatively cool while the side walls of the heat exchanger become relatively hot. It is a principal object of this invention to provide means to heat the bottom wall of the heat exchanger thereby providing more hot, effective heat exchanger surface. A reduction in the amount of metal wall surface that must be provided in the heat exchanger and a resulting cost saving are thus made possible.

It is also an object of the invention to provide burner means for directing heat toward one side of the bottom wall of a heat exchanger while a blower directs relatively cool air against the other side of the bottom wall. The cooling accomplished by the blower prevents the temperature of the bottom wall from becoming so excessive as to damage it. By thus cooling the bottom wall to a limited extent it becomes unnecessary to use an alloy steel or other heat resistant material, the cost of which would be prohibitive.

Thus it is an object of the invention to provide means to elevate the temperature of the bottom wall of a furnace heat exchanger so that it has a higher temperature than heretofore, but means are also provided to keep the temperature of the bottom wall below a reasonable upper limit.

In the drawings:

Fig. 1 is a side view, with parts of the casing broken away, illustrating my invention as applied to a hot air furnace;

Fig. 2 is a front elevational view of the furnace, with parts of the casing broken away;

F Fig1. 3 is a sectional view taken on the line 33 of 4 is a sectional view taken on the line 4-4 of 1g.

Fig. 5 is a plan view of the burner incorporating my invention; V

Fig. 6 is a side elevational view thereof;

Fig. 7 is a longitudinal sectional view taken on the line 77 of Fig. 5; p

Fig. 8 is an end elevational view taken in the direction of the arrow 8 of Fig. 5;

Figs. 9 and 10 are sectional views taken on the lines 9-9 and 10-1l), respectively of Fig. 5; and

Fig. 11 is a diagrammatic View showing the flame pattern relative to the heat exchanger surfaces.

A furnace 10 is illustrated in Fig. 1 and includes an outer casing 12 which is subdivided by a partition 14 into an upper chamber 16 and a lower chamber 18. The casing 12 is provided with an air inlet opening 20 in a side 2,975,917 Patented Mar. 28, 1961 wall of lower chamber 18 and a blower 22 of conventional construction depends from partition 14 and has an air outlet portion 24 penetrating an opening 26 in partition 14 so that the blower is able to draw air into the furnace through opening 18 and discharge such air upwardly into the upper chamber 16.

In order to heat the air dischargedv by blower 22 into chamber 16 a heat exchanger 28 is supported in the upper chamber 16 of casing 12. The air discharged upwardly by blower 22 travels up through the upper chamber 16 in a space provided between the heat exchanger 28 and the walls of casing 12 until it is discharged through the top of casing 12 into a duct 30 of conventional construction. Duct 30 serves to distribute the heated air to different portions of the building in a manner well-known in the art. 7

The heatex'changer 28 is provided with corrugated side walls to increase the heat transfer surface of theheat exchanger and a gas burner 32, which will be described herein, is located in close proximity to a bottom wall 34 of the heat exchanger. An upper baffle 36 and an intermediate bafile 38 are provided in the heat exchanger to force heated air into contact with the outer walls of the heat exchanger 28. Referring to Fig. 3 it will be noted that the bafile 38 is spaced from the heat exchanger wall substantially around its periphery so that the heated air is forced outwardly into contact with the heat exchanger walls in order to get by the bafile 38. The baffle 36, as illustrated in Fig. 4, is spaced from the heat exchanger walls along its forward edge and a portion of its sides. The heated air after it has passed the baflie 36 is conducted thereby to a conventional manifold 40 and flue 42.

The gas burner 32, which was briefly mentioned above, is supported upon the bottom wall 34 of the heat exchanger 28 by means of a short leg 44. A pair of laterally extending ears 45 are provided for mounting on suitable supporting structure (not illustrated) carried by furnace casing 12. The burner 32 is adapted to receive gas through an inlet pipe 46 and combustion air through an adjustable aperture 48 in the end of the burner. The burner 32 includes a hollow body portion 59 provided with an upwardly directed orifice 52. The burner 32 further includes a substantially horizontally disposed spreader plate 54 which is supported by body portion Stlby means of a depending tongue 56 at the rear portion of the spreader plate and a pair of support elements 58 at the front portion of the spreader plate. The depending tongue 56 is received in a groove 57 illustrated in Figure 7 and provided on the upper surface of the burner body portion 56. The spreader plate 54 is provided with a plurality of downwardly directed peripheral portions 60 so that combustible material which is emitted from the burner from orifice 52 thereof is deflected laterally by spreader plate 54 and then directed downwardly by peripheral portions 68 toward the bottom wall 34 of the heat exchanger 28. Re-

ferring to Fig. 11 it will be seen that the flame is directed downwardly toward the bottomwall 34 and then rises and sweeps the vertical walls of the heat exchanger 28. The burner body portion 50 is preferably provided, with an integral laterally extending flange or boss .55 suitable for supporting a conventional pilot light fixture which has not been illustrated herein.

It will be noted that the bottom wall 34 of the heat exchanger is heated by the close proximity of the flame to it. In order, however, that the temperature of the bottom wall be controlled so that it does not become ex-- cessively heated the air outlet portion of the blower 22 is arranged to discharge atmospheric air directly against the outer surface of the bottom wall of heat exchanger. If the blower 22 was not utilized to keep the temperature of the 1 bottom wall 34 within certain limits it might be necessary to form such a wall from alloy materials capable of withstanding extreme temperatures. This would be undesirable because of the prohibitive cost involved.

We claim: p

In a hot air furnace a hollow heat exchanger of rectangular horizontal section having vertical side walls and a bottom wall, and a gas burner mounted in close proximity to said bottom wall and within said heat exchanger, said burner including a generally horizontal inspirator tube having an axisv extending normal to one of said vertical side walls and upwardly directed orifice means located above a central region of said bottom wall with the marginal portion of said orifice means located substantially in a horizontal plane, said burner further including a spreader plate overlying and having a greater width than the above mentioned orifice means, said spreader plate'including a flat main body portion which is substantially rectangular in plan View with its major axis parallel to said side walls and aligned with the axis of said inspirator tube and with one end portion thereof extending transversely of said inspirator tube, said flat main body portion of said spreader plate lying in a horizontal plane spaced slightly above the marginal portion of said orifice means with the above mentioned end portion of said spreader plate and said inspirator tube being operatively connected throughout the entire width of said inspirator tube, the remaining end portion and both side portions of the rectangular spreader plate body portion cooperating with the marginal portion of said orifice means to provide a continuous slot adapted to serve as one uninterrupted port of uniform section extending around three sides of the rectangular spreader plate body portion to accommodate the escape of an air and gas mixture in horizontal directions therefrom, said spreader plate also being provided with a downwardly inclined peripheral portion on each of its last mentioned three sides serving to direct the escaping gas and air mixture toward said bottom wall.

References Cited in the file of this patent UNITED STATES PATENTS 2,214,269 Bryant Sept. 10, 1940 2,380,602 McCollum July 31-, 1945 2,433,618 McCollum Dec. 30, 1947 2,549,347 VanTuyl Apr. 17, 1951 2,595,739 Weseman May 6, 1952 2,772,149 Garbo Nov. 27, 1956 2,808,046 Jaye Oct. 1, 1957 FOREIGN PATENTS 492,839 Canada May 12, 1953 

